The following relates generally to wireless communication and more specifically to dynamic transmission configuration indication (TCI) state updating.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as a Long Term Evolution (LTE) systems or LTE-Advanced (LTE-A) systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform-spread-OFDM (DFT-S-OFDM). A wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
In some wireless communications systems, a base station may communicate with a UE using multiple antennas. Data streams may be mapped to one or more antennas using antenna ports, and each of these antenna ports may be associated with a reference signal (e.g., which may allow a receiver to distinguish data streams associated with different antenna ports in a received transmission). In some cases, some antenna ports may be referred to as quasi co-located, meaning that the spatial parameters associated with a transmission on one antenna port may be inferred from the spatial parameters associated with another transmission on a different antenna port. This implicit relationship between antenna ports may improve the chances that a UE is able to successfully decode a downlink transmission. For example, a receiving device (e.g., a UE) may be able to perform channel estimation for demodulating data received on a first set of antenna ports based on reference signals received on a second set of antenna ports that are quasi co-located with the first set of antenna ports. Conventional techniques for signaling, to a UE, quasi co-location (QCL) relationships between different antenna ports are inefficient and degrade the reliability of communications in a wireless communications system.